Machine for forming springs.



PA'TENTED SEPT.26, 1905. F. M. STAMBAUGH. MACHINE FOR FORMING SPRINGS;

APPLIOATION FILED MAR.7,1905.

2 sums-SHEET 1.

INVENTQR FRANC\S MSTAMBAUGH. BY. MM WM ATTEST. $09. r mm.

ATTY

FRANCIS M. STAMBAUGH, or LoUIs,

MISSOURI, ASSIGNOR TO THE AMERICAN BRAKE COMPANY, OF ST. LOUIS. MISSOURI, A CORPORA- TION OF MISSOURI.

MACHINE FOR FORMING SPRINGS.

Specification of Letters Patent.

Patented Sept. 26, 1905.

Application filed March '7, 1905. Serial No. 248,847.

To (LZZ whom it Wtay concern.-

Be it known that I, FRANCIS M. STAMBAUGH, a citizen of the United States, residing at St. Louis, Missouri, have invented a certain new and useful Improvement in Machines for Forming Springs, of which thefollowingis a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same, reference beinghad to the accompanyingdrawings,forming part of this specification, in which Figure 1 is a top plan view of my improved machine. Fig. 2 is a sectional view on the line 2 2 of Fig. 1 when the parts are in the position shown by dotted lines in Fig. 1. Fig. 3 is a sectional view on the line 3 3 of Fig 1, and Fig. 4 is a detail view of a spring formed by my improved machine.

This invention relates to a new and useful improvement in machines for forming leafsprings used in connection with air-brake couplings.

The object of this invention is to construct a simple and powerful machine which will effectually bend the metal into the desired shape, so that the springs will all be uniform.

The particular machine shown in the accompanying drawings gives to the springs the initial shape; but the shape which the metal constituting the springs ultimately takes is imparted by another machine, which is shown in a companion application filed by me of even date herewith and serially numbered 248,850.

In the drawings, 1 indicates a suitable frame, on which is mounted a bed-plate 2. This bed-plate has secured thereto a block 3, whose inner face is formed to the shape desired to be given the metal to be bent; Block 3 is provided with a stop-shoulder 4:, against which the blank to be shaped is placed. Block 3 is also provided with lugs or ears 5, between which is pivoted a movable jaw 6, having a face corresponding in shape to the face of the die-block 3. The jaw 6 is actuated by a toggle mechanism comprising links 7 and 8, the former of which is pivotally connected to the free end of jaw 6 and to the cross-head 9 of a piston-rod, while the latter is pivotally connected to said cross-head and also to a fixed pivot 10, arranged on the base 2. With respect to the pivotal connections of the links 7 and 8 to their respective parts it will be noted that the jaw 6 is provided with appropriate sockets for receiving the end of lever 7 and that there are two of such levers 7 (see Fig. 2) arranged above and below the strengthening-rib of the jaw 6. The opposite ends of lever 7 are correspondingly curved and seated in sockets in the cross-head 9 of the piston-rod. Levers 8 are similarly socketed in the cross-head 9; but at their fixed point of attachment to the base saidlevers 8 are connected and socketed in an abutment extending up from said base. The purpose of this is to relieve the pivot-bolts of transverse strain and transmit the load imposed upon the levers directly onto the respective sockets with which they cooperate.

The piston which carries the cross-head 9 is mounted in acylinder 11, trunnioned into the base-plate 2 (see Fig. 3) by means of a pivot-stud 12, whereby said piston may oscillate and accommodate itself to the arc of movement described by the links 8.

Pressure, preferably in the form of compressed air, is admitted and exhausted to and from the spaces behind and in front of the cylinder 11- through pipes 13 and 14:, which have flexible portions permitting the oscillatory movement of the cylinder, said pipes leading to a valve 15, which controls the sup ply of air passing through pipes 16, leading from some suitable source. The exhaust-air is conducted from valve 15 by means of a pipe 17 to a point between the movable and fixed dies, so that the exhaust is utilized in blowing ofi the scale from the blank and also preventing the accumulation of scale between the fixed and movable dies.

In operation the blank to be formed is first heated in a suitable furnace and then inserted between the dies, preferably against the shoulder 4. Valve 15 is then opened to admit pressure behind the piston in cylinder 11 and exhaust-pressure from in front of said piston, whereby the movable die swings on its pivot, its first engagement with the blank being through the medium of the forming projection 6, which is located near the pivotal point. This projection 6 in first engaging the-blank tends to force the blank against the shoulder i, and immediately that the home position of the blank isreached the bending action commences, which bending action cramps the blank, so that the displaced portions will be drawn from the free end of the blank and not from the cramped end. It will be seen that the free end of the blank while the projection 6 is operating is not engaged and may thus be readily drawn upon or foreshortened, the final movement of the pivoted jaw 6 engaging the free end of the blank and forcing it to assume its final shape. It is not necessary to allow the jaw 6 to remain closed upon the blank for any considerable length of time, as the metal of the blank being heated readily sets in the desired shape, and therefore the valve 15 may be so operated as to exhaust the pressure from behind the piston and admit pressure in front of said piston, so

as to open the jaw 6. This exhaust-pressure is directed by pipe 17 against the blank and between the dies, so that it tends to remove the free scales;

After the blank is formed by this machine it is subsequently operated upon by the machine shown in my aforesaid companion application, which gives to the blank its ultimate shape, the finished spring then being tempered in oil for well-understood purposes. I have found that it is not-necessary to reheat the blank after it is initially operated upon by the machine shown in the present application and before it is submitted to the finishing-machine shown in my companion application. In practice the two machines are placed close together and the blankas initially shaped is taken and immediately attached to the former of the finishing-machine.

Having thus described the invention, what is claimed as new, and desired to be secured by Letters Patent, is

1. In a metal-bending machine, the combination with a bed-plate, of an oscillatory piston mounted thereon, toggle-levers pivotally connected to said piston, a fixed fulcrum on the bed plate with which one of said togglelevers cooperates, a movable die pivotally mounted upon the bed-plate with which the other of said toggle-levers cooperates, and a fixed die cooperating with said movable die; substantially as described.

2. In a metal-bending machine, the combination with a bed-plate, of an oscillatory cylinder mounted thereon, a fluid-actuated piston arranged in said cylinder, a valve for admitting and exhausting pressure behind or in front of said piston, links 7 and 8 pivotally connected to said piston, link 8 having a fixed fulcrum on the bed-plate, a pivotally-mounted jaw to which the link 7 is connected, and a fixed die with which said jaw cooperates; substantially as described.

3. In a sheet-metal-bendin'g machine, the combination with a fixed former and a pivoted movable former, of a toggle mechanism connected to the movable former, a power device comprising a fluid-actuated piston for operating said toggle mechanism, an exhaustpipe leading from said power device for directing the exhaust-pressure between the dies for the purpose of removing the scale, and a regulating-valve in said exhaust-pipe; substantially as described.

In testimony whereof I hereunto affix my signature, in the presence of two witnesses, this 3d day of March, 1905.

FRANCIS M. STAMBAUGH'.

Witnesses:

EDWARD VVILsoN,v GEORGE BAKEWELL. 

